Piston wrist pin setting tool



March 17, 1942. H. 'H. HERRIG PISTON WRIST PIN SETTING TOOL Filed Jan.25, 1941 HarveyHf/crrjg.

Patented Mar. 17, 1942 U N i T E 4 Claims.

The present invention relates to tools to be applied to wrist pins,bushings, or the like for rotating or moving the same axially orlongitudinally of the object or piece of work in which they areinserted.

In many instances, after a wrist pin has been placed in a piston, itbecomes necessary to align a radial hole in the wrist pin with a likehole in one of the piston bearings which receive the wrist pin, so thata keeper bolt or set screw may be inserted in the aligned holes tosecure the wrist pin against rotation. Considerable difficulty may beencountered in aligning these holes unless a tool constructedparticularly for this purpose is available.

The present tool is constructed particularly for such use and includesmeans for guiding and facilitating the insertion and removal of the toolfrom a wrist pin or bushing.

With the foregoing and other objects in view,

the invention will now be more fully described, reference being had tothe accompanying drawing in which:

Figure 1 is a perspective of the tool constituting the presentinvention.

Figure 2 is a side elevation of the tool inserted in a wrist pin, and

Figure 3 is a sectional view of a piston and wrist pin after the presenttool has been utilized in aligning the holes in the pin and piston sothat a set screw or keeper bolt may be'applied.

Referring now to the drawing, the numeral Hi designates generally thetool of the present invention. This tool comprises a rigid body or headll having a cylindrical surface or annular surface 12 which is ofsubstantially the same circumference as the inside circumference of awrist pin or bushing to which the tool is to be applied. A lug ISprojects radially from what may be considered the top of the tool andthis lug lies within the confines of the cylindrical surfaceor annularportion I2 as clearly shown in Figures 1 and 2.

The body portion is provided with a curved and What may be considered apartially spheri- The reduced por-.

tion 15 is on the opposite side of the cylindrical surface l2 from theportion I 4, that is, the portion I5 is adjacent the top of the tool anddirectly in rear of the lug l3.

The body I l is also provided with a raised portion it directly in rearof the reduced portion I5 and constituting an abutment for engaging theedge of a wrist pin to limit the inward movement of the tool within thewrist pin and permitting the tool to swing about the edge of the wristpin as a pivot so that the lug I3 may be guided into a radial hole inthe wrist pin, as will be described in greater detail hereinafter.

The opposite sides of the raised portion l6 of the body gradually mergeinto a more pronounced enlargement forming a flange I! which engages therear lower portion of the cylindrical surface or annular portion l2.This flange l1 constitutes an abutment adapted to contact the edge ofthe wrist pin and limit the movement of the body I l as the tool isinserted into the Wrist pin.

The tool is provided with a handle l8 joining the body portion andforming therewith an integral rigid tool. The portion of the handleadjacent the body is provided with a plurality of flat surfaces forminga squared area Hi to accommodate a wrench 20 whereby the tool may berotated after its insertion into the wrist pin so as to align up theradial holes in the pin and piston.

Referring to Figure 2, there is disclosed a sectional view of a piston2| having registering bearings 22 and 23. Bearing 23 is provided with athreaded hole or opening 24. The numeral 25 represents a Wrist pin orpiston pin which has been inserted in the piston within the bearings 22and 23. This wrist pin may be of a well known construction which isprovided with a radial hole or opening 26 adjacent one end thereof. Inmany instances, aftera wrist pin of this type has been inserted into itspiston, it is necessary that the hole 26 be aligned with the hole 24 inthe piston bearing 22 so that a set screw or keeper bolt may be screwedinto the aligned holes to secure the wrist pin in the piston againstboth longitudinal and rotary movement therein. If these two holes arefor any reason out of register, it becomes necessary to align the holesand this is quite a difficult operation unless the correct type of toolis available. The tool of the present invention is designed particularlyfor such use and may be easily and quickly applied to a wrist pin.

The initial step of inserting the present tool into a wrist pin is shownin dotted lines in Figure 2. As illustrated in this view, the tool ispartially inserted at an angle to the longitudinal axis of the wrist pinand this is facilitated because of the reduced portions I4 and I5,formed in the body of the tool. The tool is inserted until the raised orenlarged top portion [6 abuts the edge of the wrist pin. The abutment I6is also spaced from the lug [3 a distance to permit the lug to bereadily inserted into the hole 26 by swinging the tool about the end ofthe wrist pin as a pivot. In other words, after the tool has beenapplied as shown in the dotted line position of Figure 2, the handleportion is then swung downwardly to the full line position. This raisesthe body so that the lug l3 enters the hole 25. Any further movement ofthe handle which may tend to jam the tool in the wrist pin or the lug inthe opening 26, is prevented .by reason of the fact that the flange orlower abutment I! immediately contacts the edge of the wrist pin, afterthe lug enters the hole 26. This prevents any further inward swingingmovement of the tool.

After the tool has been inserted into the wrist pin as above described,a wrench 20 or other suitable tool may be applied to the squared portionIQ of the handle to rotate the tool. This rotation is imparted to thewrist pin so that the hole 26 may align with the hole or opening 2G inthe bearing 22. After the holes have been aligned and while the tool isstill inserted within the wrist pin, the set screw 28 may be screwedinto the threaded opening 24 so that its inner end will project slightlyinto the opening 26. It will be observed that the lug i3 is purposely ofa thickness so that it will not entirely fill the hole. This providesclearance to permit the inner end of the screw 28 to initially enter thehole 26. Thereafter the tool Iii may be easily and quickly removed byswinging the handle l8 downwardly so that the lug is removed from thehole 25. The reduced portions 14 and I5 permit the tool to be removed inthis manner without any binding or jamming. By further screwing up onthe set screw 28, it will entirely enter the hole 26, so as to rigidlysecure the piston pin in the piston against longitudinal and rotarymovement, as clearly shown in Figure 3. If desired, a lock nut 29 may bethreaded on the screw 28.

Figure 2 of the drawing shows the opening 26 of the wrist pin asinitially being diametrically opposite the threaded opening 24. This hasbeen done primarily to illustrate the tool to its best advantage. It isto be understood that in many instances the piston pins will beinitially inserted in the piston so that the holes 24 and 25 are moreclosely aligned. It is to be further understood that wrist pins ofdifferent sizes and diameters will require tools of varying sizes.However, since these motor parts are usually made in standard sizes, itwill require the use of a relatively few tools to take care of thediiierent types and sizes of piston pins. It is also to be understoodthat the present tool may also be used as a bushing puller or remover.In this connec tion, if it is merely desired to remove a bushing or thewrist pin 25, this may be accomplished by pulling outwardly upon thehandle IS. The greater portion of the handle is preferably serrated orroughened to provide a firm grip. Furthermore a hole 29 is formed in thehandle so that a bar or tool may be inserted to facilitate eitherrotation of the tool or a longitudinal movement thereof, such as isnecessary to remove a bushing.

It will be observed that the extreme end of the body H is provided witha flattened portion 30. If desired the curved portion [4 may be extendedto include the portion 30 so as to form a substantially semi-sphericalarea. This is optional, since the operation of the tool or its coactionwith the wrist pin would not be changed or afiected.

It is to be understood that the form of the invention shown anddescribed is illustrative of the preferred embodiment, and that suchchanges may be made without departing from the spirit of the inventionas fall within the purview of one skilled in the art and the scope ofthe appended claims.

I claim:

1. A tool for use with hollow wrist pins or the like, comprising a rigidbody adapted to be inserted into an end of a wrist pin and provided witha cylindrical surface of substantially the same circumference as theinside circumference of the wrist pin and adapted when inserted in theend of a wrist pin to have a relatively close fit with the inner surfaceof the pin, and a lug projecting radially from the cylindrical surfaceof said rigid body for engagement with a radial hole formed in andadjacent one end of the wrist pin, said lug cooperating with saidcylindrical surface to detachably lock the tool to the wrist pin topermit rotation of the wrist pin, said body being provided with spacedreduced portions at opposite sides of the cylindrical surface to provideclearance to permit insertion and removal of the tool without anybinding between the tool and interior of the wrist pin, said body havinga substantially semi-circular flange projecting radially therefrom andjoining the cylindrical surface on the portion of the body opposite thelug and constituting an abutment for engaging an end of the wrist pinwhen the tool is finally moved to operative position.

2. A tool for use with hollow wrist pins or the like comprising a rigidbody adapted to be inserted into an end of a wrist pin and providedwitha cylindrical surface of substantially the same circumference as theinside circumference of the wrist pin and adapted when inserted in theend of a wrist pin to have a relatively close fit with the inner surfaceof the pin, a lug projecting radially from the cylindrical surface ofsaid body for engagement with a radial hole formed in and adjacent oneend of the wrist pin, said lug cooperating with said cylindrical surfaceto detachably lock the tool to the wrist pin to permit rotation of thewrist pin, said body having a partially spherical portion extending fromone end thereof to the cylindrical surface at a point opposite the lug,said body having a reduced portion in rear of said lug and on theopposite side of the cylindrical surface from the partially sphericalportion and cooperating therewith to provide clearance to permitinsertion and removal of the tool without any binding between the tooland interior of the wrist pin, said body having a raised portion in rearof said reduced portion and in line with said lug and constituting anabutment for engaging the edge of the wrist pin to limit the inwardmovement of the tool within the wrist pin and permit the tool to swingand guide the lug into engagement with the hole in the wrist pin.

3. A tool for use with hollow wrist pins or the like comprising a rigidbody adapted to be inserted into an end of a wrist pin and havingportions thereof arranged in a circular path and adapted to engage andhave a close fit with the inner surface of the wrist pin, and a lugprojecting radially from said body for engagement with a radial holeformed in and adjacent one end of the wrist pin, said lug being rigidlyattached to said body, said body being provided with spaced reducedportions to provide clearance by a swinging movement to permit insertionand removal of the tool without any binding between the tool andinterior of the wrist pin, one of said reduced portions being in rear ofsaid lug, said body having a raised portion in rear of said lastmentioned reduced portion and in line with said lug and constituting anabutment for engaging an edge of the wrist pin to limit the inwardmovement of the tool within the wrist pin and permit the tool to swingand guide the lug into engagement with the hole in the wrist pin.

4. A tool for use with hollow wrist pins or the like, comprising a rigidbody adapted to be inserted into an end of a wrist pin and provided witha cylindrical surface of substantially the same circumference as theinside circumference of the wrist pin and adapted when inserted in theend of a Wrist pin to have a relatively close fit with the inner surfaceof the wrist pin, and a lug rigidly connected to and projecting radiallyfrom the cylindrical surface of said body for engagement with a radialhole formed in and adjacent one end of a wrist pin, said lug cooperatingtherewith to detachably lock the tool to the wrist pin to permitrotation of the Wrist pin, said body being provided with spaced reducedportions, one located behind the lug and the other located at theforward edge of the body on the side opposite the lug to provideclearance to permit insertion and removal of the tool by a swingingmovement without any binding between the tool and the interior of thewrist pin.

HARVEY H. HERRIG.

